Thank you all for your valuable contributions in my undying quest!
Hi Jorge,
"Sorry, but the IRFI640G is known to sounds veiled."
Hi Chocoholic
"You are only sharing half of the truth with us."
Another night of meditation, mantra chanting, and revelations.
As you know my mate went into surgery yesterday on his ear. Well they had difficulty fitting him in. You see Australians are basically a healthy lot and the only reason the hospitals are in overload is that they're all having elective surgery to further extend their lives , such as triple bypasses at 45, lung transplants (70,000 die each year from pollution related disease) and leukemia (australia still puts benzene in its fuel), and my old mate with his septic ear.
Well they found an opening for him - in the open plan birthing ward, right next to the MRI. Well, apparently he came out of surgery and fell out of bed. While he was on the floor, he noticed a small 3 legged black thing! No, it wasn't jake the peg's illegitimate child but a MOSFET! It had Samsung P240 on it! He asked the nurse about it and she said the "happy f*nny" MRI (only the best for OZ hospitals) had had an upgrade with more powerful field coils and there were 2 of these devices left over. "Where was the other one?" he asked, knowing you need 2 for stereo. "Well it went missing after surgery"!
To cut a long story short, my mate brought it home and I plugged it in instead of that veiled IRFI640G - and what a revelation. It was astonishing! Only one channel of course but my mate reckons at least 60% of the soundstage height and depth is still there with only one channel.
So as sure as 2x60% is 120% we'll be 20% ahead on imaging and detail IF I CAN SOURCE ANOTHER Samsung P240!
Oh, here's more - while he was still in hospital and thinking it could be a equiv to IRFP240, he put it under the MRI to look for a hex structure. What he found wes indeed another revelation - the chip was an icosadodecahedron buckyball fullerene! Yep! It seems the design engineer used to holiday at Big Sur and got his inspiration there.
A very desirable component I would say. The revelations just keep coming.
Cheers,
Greg
Hi Jorge,
"Sorry, but the IRFI640G is known to sounds veiled."
Hi Chocoholic
"You are only sharing half of the truth with us."
Another night of meditation, mantra chanting, and revelations.
As you know my mate went into surgery yesterday on his ear. Well they had difficulty fitting him in. You see Australians are basically a healthy lot and the only reason the hospitals are in overload is that they're all having elective surgery to further extend their lives , such as triple bypasses at 45, lung transplants (70,000 die each year from pollution related disease) and leukemia (australia still puts benzene in its fuel), and my old mate with his septic ear.
Well they found an opening for him - in the open plan birthing ward, right next to the MRI. Well, apparently he came out of surgery and fell out of bed. While he was on the floor, he noticed a small 3 legged black thing! No, it wasn't jake the peg's illegitimate child but a MOSFET! It had Samsung P240 on it! He asked the nurse about it and she said the "happy f*nny" MRI (only the best for OZ hospitals) had had an upgrade with more powerful field coils and there were 2 of these devices left over. "Where was the other one?" he asked, knowing you need 2 for stereo. "Well it went missing after surgery"!
To cut a long story short, my mate brought it home and I plugged it in instead of that veiled IRFI640G - and what a revelation. It was astonishing! Only one channel of course but my mate reckons at least 60% of the soundstage height and depth is still there with only one channel.
So as sure as 2x60% is 120% we'll be 20% ahead on imaging and detail IF I CAN SOURCE ANOTHER Samsung P240!
Oh, here's more - while he was still in hospital and thinking it could be a equiv to IRFP240, he put it under the MRI to look for a hex structure. What he found wes indeed another revelation - the chip was an icosadodecahedron buckyball fullerene! Yep! It seems the design engineer used to holiday at Big Sur and got his inspiration there.
A very desirable component I would say. The revelations just keep coming.
Cheers,
Greg
Well thank you for the emails - informing me that you really don't want to use a 2KW tranny and 279,000uF to have such a good low power amplifier, so I have reluctantly made the necessary modification to render the amplifier less sensitive to supply borne hash.
Yes it's the CCS for input stage tail current.
Imagine 1Vrms of ripple plus output commutation harmonics,lots of them 2nD,4th,6th,8th,... Ivrms on a 50V supply would modulate the stage current by 2% which will in turn modulate the IK current to the next stage by 2% from where it will be amplified by the very high Vas gain indistinguishable from signal! The over the top supply would suppress this. If we change to the CCS the divider is now the LED impedance/100K+collector - more like 0.005% and lower at high frequencies when the C across it lowers it's impedance.
Shown also is the original 31.4K which could still be inserted to ground to retain common mode signal induced 2% modulation for harmonic doctoring of the sound - but without the supply borne hash obscuring the detail.
My mate and I feel this is a far more stable design and much less needy of excessive Power supplies to perform.
Back with audition results.
Yes it's the CCS for input stage tail current.
Imagine 1Vrms of ripple plus output commutation harmonics,lots of them 2nD,4th,6th,8th,... Ivrms on a 50V supply would modulate the stage current by 2% which will in turn modulate the IK current to the next stage by 2% from where it will be amplified by the very high Vas gain indistinguishable from signal! The over the top supply would suppress this. If we change to the CCS the divider is now the LED impedance/100K+collector - more like 0.005% and lower at high frequencies when the C across it lowers it's impedance.
Shown also is the original 31.4K which could still be inserted to ground to retain common mode signal induced 2% modulation for harmonic doctoring of the sound - but without the supply borne hash obscuring the detail.
My mate and I feel this is a far more stable design and much less needy of excessive Power supplies to perform.
Back with audition results.
Attachments
thanks Ashok & Jorge,
points noted and have morphed the wole design to something at least workable.
Trust it meets with your approval. Note in particular the "bloom" control to introduce common mode nonlinearity while retaining PSRR - for those who like to 'colour' their sound. In reality such a control could easily be added to any CCS input diff'l stage.
Cheers,
Greg
points noted and have morphed the wole design to something at least workable.
Trust it meets with your approval. Note in particular the "bloom" control to introduce common mode nonlinearity while retaining PSRR - for those who like to 'colour' their sound. In reality such a control could easily be added to any CCS input diff'l stage.
Cheers,
Greg
Attachments
amplifierguru said:
I think you need this famous device: http://www.rane.com/pi14.html , the Pseudoacoustic Infector.
Steven
Hi Jacco,
Yes it all comes down to pornography, what we'll do for money?
Obscene power supplies.
Ultima Thule,
"is this the new "AKSA-branch" WITH trimable "sound" from OZ?"
Hugh? Hello?
Stephen,
I like that - but that's a joke, right? Here I'm trying to solve one of the great dilemma's of audio manufacturers - to design clean or euphonic amplifiers! Can I sense NP reaching for that fast track to another notch on the patent (leather) belt? Of course not.
cheers,
Greg
Yes it all comes down to pornography, what we'll do for money?
Obscene power supplies.
Ultima Thule,
"is this the new "AKSA-branch" WITH trimable "sound" from OZ?"
Hugh? Hello?
Stephen,
I like that - but that's a joke, right? Here I'm trying to solve one of the great dilemma's of audio manufacturers - to design clean or euphonic amplifiers! Can I sense NP reaching for that fast track to another notch on the patent (leather) belt? Of course not.
cheers,
Greg
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